feat!: migrate to OpenAI native tool calls and fix circular deps (#fuck-gemini)

- Fix circular dependencies in agent/tools
- Migrate from custom JSON to OpenAI tool calls format
- Add async streaming (step_stream, complete_stream)
- Simplify prompt system and remove token counting
- Add 5 new API endpoints (/health, /v1/models, /api/memory/*)
- Add 3 new tools (get_torrent_by_index, add_torrent_by_index, set_language)
- Fix all 500 tests and add coverage config (80% threshold)
- Add comprehensive docs (README, pytest guide)

BREAKING: LLM interface changed, memory injection via get_memory()

application/filesystem/dto.py

@@ -1,21 +1,22 @@
 """Filesystem application DTOs."""
+
 from dataclasses import dataclass
-from typing import Optional, List
 
 
 @dataclass
 class SetFolderPathResponse:
     """Response from setting a folder path."""
+
     status: str
-    folder_name: Optional[str] = None
-    path: Optional[str] = None
-    error: Optional[str] = None
-    message: Optional[str] = None
-    
+    folder_name: str | None = None
+    path: str | None = None
+    error: str | None = None
+    message: str | None = None
+
     def to_dict(self):
         """Convert to dict for agent compatibility."""
         result = {"status": self.status}
-        
+
         if self.error:
             result["error"] = self.error
             result["message"] = self.message
@@ -24,25 +25,26 @@ class SetFolderPathResponse:
                 result["folder_name"] = self.folder_name
             if self.path:
                 result["path"] = self.path
-        
+
         return result
 
 
 @dataclass
 class ListFolderResponse:
     """Response from listing a folder."""
+
     status: str
-    folder_type: Optional[str] = None
-    path: Optional[str] = None
-    entries: Optional[List[str]] = None
-    count: Optional[int] = None
-    error: Optional[str] = None
-    message: Optional[str] = None
-    
+    folder_type: str | None = None
+    path: str | None = None
+    entries: list[str] | None = None
+    count: int | None = None
+    error: str | None = None
+    message: str | None = None
+
     def to_dict(self):
         """Convert to dict for agent compatibility."""
         result = {"status": self.status}
-        
+
         if self.error:
             result["error"] = self.error
             result["message"] = self.message
@@ -55,5 +57,5 @@ class ListFolderResponse:
                 result["entries"] = self.entries
             if self.count is not None:
                 result["count"] = self.count
-        
+
         return result